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Generation and propagation of 21-day bottom pressure variability driven by wind stress curl in the East china Sea

Acta Oceanologica Sinica 2020年第7期39卷 91-106页

作者： Hua Zheng Xiao-Hua Zhu Hirohiko Nakamura Jae-Hun Park Chanhyung Jeon Ruixiang Zhao Ayako Nishina Chuanzheng Zhang Hanna Na Ze-Nan Zhu Hong-Sik Min State Key Laboratory of satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Faculty of Fisheries Kagoshima UniversityKagoshima 8900056Japan department of Ocean Sciences Inha UniversityIncheon 22212Korea department of Mechanical Engineering Massachusetts Institute of TechnologyCambridge 02139USA School of Earth and Environmental Sciences Seoul National UniversitySeoul 08826Korea Ocean Circulation and Climate Research center Korea Institute of Ocean Science and TechnologyBusan 49111Korea

Between June 2015 and June 2017,two pressure-recording inverted echo sounders(PIESs)and five current and pressure-recording inverted echo sounders(CPIESs)deployed along a section across the Kerama Gap acquired a dataset of ocean bottom pressure records in which there was significant 21-day variability(Pbot21).The Pbot21,which was particularly strong from July-December 2016,was coherent with wind stress curl(WSC)on the continental shelf of the East china Sea(ECS)with a squared coherence of 0.65 for a 3-day time lag.A barotropic ocean model demonstrated the generation,propagation,and dissipation of *** modeled results show that the Pbot21 driven by coastal ocean WSC in the ECS propagated toward the Ryukyu Island Chain(RIC),while deep ocean WSC could not induce such *** the continental shelf,the Pbot21 was generated nearly synchronously with the WSC from the coastline to the southeast but dissipated within a few days due to the effect of bottom *** detection of Pbot21 by the moored array was dependent on the 21-day WSC patterns on the continental *** Pbot21 driven southeast of the Changjiang Estuary by the WSC was detected while the Pbot21generated northeast of the Changjiang Estuary was not.

关键词： pressure-recording inverted echo sounder East china Sea bottom pressure wind stress curl

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Formation and evolution mechanism of metal whiskers in extreme aerospace environments:A review

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中国航空学报:英文版 2023年第9期36卷 1-13页

作者： Zekun WANG Shiming WANG School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444China department of Mechanical Engineering Auburn UniversityAuburn AL 36849USA College of Engineering Science and technology Shanghai Ocean UniversityShanghai 201306China Shanghai Engineering Research center of Marine Renewable Energy Shanghai 201306China

The spontaneous growth and evolution mechanism of metal whiskers have long been scientific *** the development of the integration of electronic and electrical productions,short circuits and system failures are raised by metal whiskers *** the meantime,the related theories and mechanisms of whiskering problem are still vague,leading to a deficiency in the studies of environmental factors influencing the whisker ***,the extreme environments such as aerospace,have been proven the accelerators to the formation of metal whiskers,resulting in a severe threaten to equipment and devices working in such environments including satellite and military *** establish a comprehensive understanding to the whiskering process associated with their applicable control strategies,this study analyzes the growth phenomenon,influencing factors,formation process and evolution mechanism of metal whiskers in extreme service environments,puts forward the corresponding controlling strategies,offers a reference for the establishment of Chinese extreme aerospace strategic environment,and improves the reliability of aerospace systems.

关键词： Aerospace Extreme environments Control strategy Metal whisker Reliability

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Sand flux estimation during a sand-dust storm at Tazhong area of Taklimakan Desert, china

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Journal of Arid Land 2011年第3期3卷 199-205页

作者： XingHua YANG XiaoLiang XU Qing HE Ali Mamtimin Bo YU ShiHao TANG Institute of Desert Meteorology China Meteorological Administration Urumqi 830002 China Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Desert Atmosphere and Environment Observation Experiment of Taklimakan Station Tazhong 841000 China Graduate University of Chinese Academy of Sciences Beijing 100049 China National satellite Meteorological center China Meteorological Administration Beijing100081 China

In this paper, the sand transport during a sand-dust storm in the Tazhong area of the central Taklimakan Desert from 11：29 to 23：56 on July 19, 2008 was observed and measured in real time. The sand flux at Tazhong was estimated using sand transport empirical formulas. The critical friction velocity at Tazhong was 0.24 m/s and the functional relation between the wind speed and sediment discharge at the height of 2 m was established. It was also found that the calculated values by Lettau＇s sediment discharge formula were close to those of the instrument measurements. The horizontal sand flux and the vertical sand flux during this sand-dust storm at Tazhong were respectively 258.67×10-4 kg/（m·s） and 40.07×10-7 kg/（m2·s）.

关键词： friction velocity sand transport flux Taklimakan Desert

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Trajectory planning and base attitude restoration of dual-arm free-floating space robot by enhanced bidirectional approach

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Frontiers of Mechanical Engineering 2022年第1期17卷 2-17页

作者： Zongwu XIE Xiaoyu ZHAO Zainan JIANG Haitao YANG Chongyang LI State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Robotic System department Jiangsu Jitri-Hust Intelligent Equipment TechnologyWuxi 214000China

When free-floating space robots perform space tasks,the satellite base attitude is disturbed by the dynamic *** disturbance of the base orientation may affect the communication between the space robot and the control center on *** this paper,the enhanced bidirectional approach is proposed to plan the manipulator trajectory and eliminate the final base attitude variation.A novel acceleration level state equation for the nonholonomic problem is proposed,and a new intermediate variable-based Lyapunov function is derived and solved for smooth joint trajectory and restorable base *** the method,the state equation is first proposed for dual-arm robots with and without end constraints,and the system stability is analyzed to obtain the system *** input modification further increases the system stability and simplifies the calculation *** are carried out in the end,and the proposed method is validated in minimizing final base attitude change and trajectory ***,the minute internal force during the coordinated operation and the considerable computing efficiency increases the feasibility of the method during space tasks.

关键词： free-floating space robot dual arm coordinated operation base attitude restoration bidirectional approach

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Warmer-Get-Wetter or Wet-Get-Wetter? A Criterion to Classify Oceanic Precipitation

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Journal of Ocean University of china 2014年第4期13卷 552-560页

作者： QIAN Chengcheng CHEN Ge department of Marine technology College of Information Science and Engineering Ocean University of China

In this study,the temporal and spatial variations of observed global oceanic precipitation during 1979-2010 are *** is found that the global trend in precipitation during this period varies at a rate of 1.5％/K of surface warming while the rate is 6.6％/K during *** precipitation is highly correlated with Sea Surface Temperature （SST） in both the temporal and the spatial patterns since the strong 1997-98 E1 Ni（n）o *** the distributions of precipitation and SST,seven oceanic regions are classified and presented using the observed Global Precipitation Climatology Project （GPCP） data and Extended Reconstructed Sea Surface Temperatures,version 3 （ERSST.v3） *** examining the mechanisms of the classified oceanic precipitation regions is conducted using the Tropical Rainfall Measuring Mission （TRMM） satellite,GFDL-ESM-2G model precipitation and SST data and Hadley center sea ice and SST version 1 （HadISST1） *** than 85％ of global oceanic precipitations are controlled by either one or both of the warmer-get-wetter mechanism and wet-get-wetter *** is estimated that a 0.5 SST signal-to-noise ratio,representing the trend of SST time series to the standard deviation,is a criterion to distinguish the mechanism of a *** the SST ratio is larger than 0.5,the precipitation of this region is controlled by the warmer-get-wetter ***,rather than the humidity,is the pivotal *** the other hand,when the SST ratio is less than 0.5,the precipitation is controlled by the wet-get-wetter *** SST variability is a significant factor contributing to the precipitation variation.

关键词： oceanic precipitation criterion global warming SST

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Review of Chinese atmospheric science research over the past 70 years: Synoptic meteorology

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Science china Earth Sciences 2019年第12期62卷 1946-1991页

作者： Zhiyong MENG Fuqing ZHANG Dehai LUO Zhemin TAN Juan FANG Jianhua SUN Xueshun SHEN Yunji ZHANG Shuguang WANG Wei HAN Kun ZHAO Lei ZHU Yongyun HU Huiwen XUE Yaping MA Lijuan ZHANG Ji NIE Ruilin ZHOU Sa LI Hongjun LIU Yuning ZHU department of Atmospheric and Oceanic Sciences Peking UniversityBeijing 100871China department of Meteorology and Atmospheric Science The Pennsylvania State UniversityUniversity ParkPA 16802USA Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China School of Atmospheric Science Nanjing UniversityNanjing 210093China National Meteorological center Beijing 100081China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China

Synoptic meteorology is a branch of meteorology that uses synoptic weather observations and charts for the diagnosis,study,and forecasting of *** refers to the specific state of the atmosphere near the Earth’s surface during a short period of *** spatial distribution of meteorological elements in the atmosphere can be represented by a variety of transient weather phenomena,which are caused by weather systems of different spatial and temporal *** is closely related to people’s life,and its development and evolution have always been the focus of atmospheric scientific research and *** development of synoptic meteorology is closely related to the development of observation systems,dynamical theories and numerical *** china,observation networks have been built since the early 1950 *** to now,a comprehensive meteorological observation systembased on ground,air and space has been *** particular,the development of a new generation of dense radar networks,the development of the Fengyun satellite series and the implementation of a series of large field experiments have brought our understanding of weather from large-scale environment to thermal dynamics,cloud microphysical structure and evolution characteristics of meso and micro-scale weather *** development of observation has also promoted the development of theory,numerical model and *** the early days,china mainly used foreign numerical ***,china has developed numerical model systems with independent intellectual property *** on the results of high-resolution numerical simulations,in-depth understanding of the initiation and evolution mechanism and predictability of weather at different scales has been *** meteorology has gradually changed from an initially independent development to a multidisciplinary approach,and the interaction between weather and the change of climate and environment has become a hot and fronti

关键词： Atmospheric sciences Synoptic meteorology Weather 70-year progresses

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Red list assessments of Chinese higher plants

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International Journal of Digital Earth 2023年第1期16卷 2762-2775页

作者： Liping Li Haining Qin Eimear Nic Lughadha Yaomin Zheng Huawei Wan Jack Plummer Melanie-Jayne R.Howes Huiyuan Liu Yangming Jiang Tuo Wang Huihui Zhao Zhanfeng Shen Huiping Huang Chinese Academy of Sciences Aerospace Information Research InstituteBeijingPeople’s Republic of China Chinese Academy of Sciences Institute of BotanyBeijingPeople’s Republic of China Royal Botanic Gardens KewRichmondUK School of International Economics and Management Beijing Technology and Business UniversityBeijingPeople’s Republic of China. satellite Environmental Application center Ministry of Ecology and EnvironmentBeijingPeople’s Republic of China. University of Chinese Academy of Sciences BeijingPeople’s Republic of China

Based on the two most recent assessments of Chinese higher plants in 2013 and 2020,of 34,450 and 39,330 species,respectively,we analysed the threatened status of Chinese higher *** 2020,around 4,088(10.39%)of the assessed species in china are threatened,2,875(7.31%)Near Threatened,27,593(70.16%)not currently threatened and categorised as Least Concern and 4,752(12.08%)categorised as Data *** in 2013,3,767(10.93%)of the assessed higher plants in china are threatened,2,723(7.90%)Near Threatened,24,296(70.53%)Least Concern and 3,612(10.48%)Data *** of the Red List Index in the two years show different patterns when using different weighting methods with the equal steps weighting method showing a slight decrease(0.91675-0.91495)and the extinction risk weighting method showing a slight increase(0.98792-0.98797).We inferred that china's threatened plant species were likely/relatively effectively ***,attention should also be given to the non-threatened species in the future as an additional strategy for their conservation,to maintain their non-threatened status.

关键词： Chinese higher plants conservation IUCN red list assessment red list index(RLI) sustainable development goals(SDGs)

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Response of the Dominant Modes of Atmospheric Circulation in the Northern Hemisphere to a Projected Arctic Sea Ice Loss in 2007

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Journal of Ocean University of china 2019年第3期18卷 589-595页

作者： FAN Tingting HUANG Fei ZHOU Xiao Key Laboratory of Physical Oceanography Ocean University of China Qingdao 266100 China Laboratory for Ocean and Climate Dynamics Pilot National Laboratory for Marine Science and Technology (Qingdao) Qingdao 266100 China Ningbo Collaborative Innovation center of Nonlinear Harzard System of Ocean and Atmosphere Ningbo University Ningbo 315211 China department of Meteorology and International Pacific Research center University of Hawaii Honolulu 96822 USA

This study revisits the Arctic sea ice extent(SIE) for the extended period of 1979-2015 based on satellite measurements and finds that the Arctic SIE experienced three different periods: a moderate sea ice decline period for 1979-1996, an accelerated sea ice decline period from 1997 to 2006, and large interannual variation period after 2007, when Arctic sea ice reached its tipping point reported by Livina and Lenton(2013). To address the response of atmospheric circulation to the lowest sea ice conditions with a large interannual variation, we investigated the dominant modes for large atmospheric circulation responses to the projected 2007 Arctic sea ice loss using an atmospheric general circulation model(ECHAM5). The response was obtained from two 50-yr simulations: one with a repeating seasonal cycle of specified sea ice concentration for the period of 1979-1996 and one with that of sea ice conditions in 2007. The results suggest more occurrences of a negative Arctic Oscillation(AO) response to the 2007 Arctic sea ice conditions, accompanied by an North Atlantic Oscillation(NAO)-type atmospheric circulation response under the largest sea ice loss, and more occurrences of the positive Arctic Dipole(AD) mode under the 2007 sea ice conditions, with an across-Arctic wave train pattern response to the largest sea ice loss in the Arctic. This study offers a new perspective for addressing the response of atmospheric circulation to sea ice changes after the Arctic reached the tipping point in 2007.

关键词： Arctic sea ice loss Arctic Oscillation Arctic Dipole atmospheric response

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Secrecy Rate Maximization for 6G Cognitive satellite-UAV Networks

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china Communications 2023年第1期20卷 246-260页

作者： Chengleyang Lei Wei Feng Yunfei Chen Ning Ge department of Electronic Engineering Tsinghua UniversityBeijing 100084China Beijing National Research center for Information Science and technology Tsinghua UniversityBeijing 100084China School of Engineering University of WarwickCoventry CV47ALUnited Kingdom

To cover remote areas where terrestrial cellular networks may not be available,non-terrestrial infrastructures such as satellites and unmanned aerial vehicles(UAVs)can be utilized in the upcoming sixth-generation(6G)*** the spectrum scarcity problem,satellites and UAVs need to share the spectrum to save costs,leading to a cognitive satellite-UAV *** to the openness of both satellite links and UAV links,communication security has become a major concern in cognitive satelliteUAV *** this paper,we safeguard a cognitive satellite-UAV network from a physical layer security(PLS)*** only the slowlyvarying large-scale channel state information(CSI),we jointly allocate the transmission power and subchannels to maximize the secrecy sum rate of UAV *** optimization problem is a mixed integer nonlinear programming(MINLP)problem with coupling *** propose a heuristic algorithm which relaxes the coupling constraints by the penalty method and obtains a sub-optimal low-complexity solution by utilizing random matrix theory,the max-min optimization tool,and the bipartite graph matching *** simulation results corroborate the superiority of our proposed scheme.

关键词： channel allocation cognitive satellite-UAV network physical layer security power allocation

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One-Dimensional Variational Retrieval of Temperature and Humidity Profiles from the FY4A GIIRS

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Advances in Atmospheric Sciences 2022年第3期39卷 471-486页

作者： Qiumeng XUE Li GUAN Xiaoning SHI Collaborative Innovation center on Forecast and Evaluation of Meteorological Disasters Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological AdministrationNanjing University of Information Science and TechnologyNanjing 210044China department of Mathematics University of Wisconsin-MadisonMadison 53706USA

A physical retrieval approach based on the one-dimensional variational(1 D-Var) algorithm is applied in this paper to simultaneously retrieve atmospheric temperature and humidity profiles under both clear-sky and partly cloudy conditions from FY-4 A GIIRS(geostationary interferometric infrared sounder) observations. Radiosonde observations from upper-air stations in china and level-2 operational products from the Chinese National satellite Meteorological center(NSMC)during the periods from December 2019 to January 2020(winter) and from July 2020 to August 2020(summer) are used to validate the accuracies of the retrieved temperature and humidity profiles. Comparing the 1 D-Var-retrieved profiles to radiosonde data, the accuracy of the temperature retrievals at each vertical level of the troposphere is characterized by a root mean square error(RMSE) within 2 K, except for at the bottom level of the atmosphere under clear conditions. The RMSE increases slightly for the higher atmospheric layers, owing to the lack of temperature sounding channels *** partly cloudy conditions, the temperature at each vertical level can be obtained, while the level-2 operational products obtain values only at altitudes above the cloud top. In addition, the accuracy of the retrieved temperature profiles is greatly improved compared with the accuracies of the operational products. For the humidity retrievals, the mean RMSEs in the troposphere in winter and summer are both within 2 g kg^(–1). Moreover, the retrievals performed better compared with the ERA5 reanalysis data between 800 h Pa and 300 h Pa both in summer and winter in terms of RMSE.

关键词： temperature and humidity profiles one-dimensional variational(1D-Var) GIIRS hyperspectral data

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